In order to detachably connect optical fibers together, use is made of optical fiber plug connectors, in whose plug connector parts, which are hollow cylindrical and consist of ceramic, the glass fibers to be coupled are intended to be bonded as centrally as possible. In this case, it is already previously known to bond short glass fibers pieces into the end regions of the plug connector parts, and to couple up the optical fibers extending into these plug connector parts to the fiber pieces with the aid of an immersion liquid. However, the advantage of exact centering of the glass fibers in the coupling region is opposed here by the disadvantage of high attentuation of the coupling points within the plug connector parts. In addition, there is the risk that the immersion liquid will dry out. The introduction of contaminants into the coupling region can scarcely be avoided when pushing the optical fiber into the associated plug connector parts.
The abovementioned disadvantages of coupling optical fibers with the aid of an immersion liquid can be avoided by welding the optical fibers. Appropriate splicing devices for welding optical fibers, such as known from U.S. Pat. No. 5,218,184, for example, are, however, not suitable for coupling glass fibers bonded into the ceramic plug connector parts to optical fibers leading, in or close to the plug connector parts.
U.S. Pat. No. 4,220,394 discloses an optical fiber plug connector whose hollow cylindrical plug connector parts have, in the region of the butt point between the bonded-in glass fiber piece and the optical fiber leading further, four openings which are arranged opposite one another in pairs. In the region of these openings, it is then possible for the two optical fibers to be welded to each other with the aid of a microwelding torch. The nozzle of the microwelding torch, which is designed as a hollow needle, is in this case introduced into one of the four openings, and the remaining openings can be used for introduction of a gripper and for the illumination and observation of the splice point.
U.S. Pat. No. 4,598,974 discloses another optical fiber plug connector whose hollow cylindrical plug connector parts, in the region of the butt point between the bonded-in glass fiber piece and the optical fiber leading further, have a splicing chamber. Two electrodes project into this splicing chamber and, by igniting an arc, effect the welding of the two optical fibers. The two electrodes are integral constituent parts of the optical fiber plug connectors, which remain on the associated plug connector parts even after the splicing operation.